#include <stdio.h>
#include <string.h>
#include <stdlib.h>


#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char *msg);

int main(int argc, char *argv[])
{
    int sock;
    char msg[BUF_SIZE];
    int str_len;
    socklen_t adr_sz;

    struct sockaddr_in serv_adr;
    struct sockaddr_in from_adr;
    if (3 != argc) {
        printf("Usage: %s <IP> <port>\n", argv[0]);
        exit(1);
    }

    sock=socket(PF_INET, SOCK_DGRAM, 0);
    if (-1 == sock) {
        error_handling("socket() error");
    }

    memset(&serv_adr, 0, sizeof(serv_adr));
    serv_adr.sin_family = AF_INET;
    serv_adr.sin_addr.s_addr=inet_addr(argv[1]);
    serv_adr.sin_port=htons(atoi(argv[2]));

    connect(sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr));

    while(1)
    {
        fputs("Insert message(q to quit): ", stdout);
        fgets(msg, sizeof(msg), stdin);

        if (!strcmp(msg, "q\n") || !strcmp(msg, "Q\n")) {
            break;
        }
        write(sock, msg, strlen(msg));

        str_len = read(sock, msg, sizeof(msg) - 1);

        msg[str_len] = 0;
        printf("Message from server: %s", msg);
    }
    close(sock);

    return 0;
}
void error_handling(char *msg)
{
    fputs(msg, stderr);
    fputc('\n', stderr);
    exit(1);
}

